BJTVoltage Divider Biasing

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Objectives At the end of the module the student

would be able to explain Study Voltage Divider Bias

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Voltage Divider Bias Circuit Provides good Q-point stability

with a single polarity supply voltage

1st step: Locate capacitors and replace them with an open circuit

2nd step: Simplified circuit using Thevenin Theorem

3rd step: Locate 2 main loops which; BE loop CE loop

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Voltage Divider Bias Circuit 1st step: Locate capacitors and replace them with

an open circuit

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Voltage Divider Bias Circuit■2nd step: : Simplified circuit using Thevenin

Theorem

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Thevenin Theorem; 21

2121 // RR

RRRRRTH

CCTH VRR

RV21

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From Thevenin Theorem;

Voltage Divider Bias Circuit■3rd step: : Locate 2 main loops.

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2

BE Loop CE Loop

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Voltage Divider Bias Circuit BE Loop Analysis

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1Recall;Substitute for IE

0 EEBETHBTH RIVRIV

ERTH

BETHB

EBBETHBTH

RRVVI

RIVRIV

)1(

0)1(

BE II )1(

Voltage Divider Bias Circuit CE Loop Analysis

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2Assume;

Therefore;CE II

0 EECECCCC RIVRIV

)( ECCCCCE RRIVV

Build the circuit as shown below and find out the following parameters IC , IB , VB, VE and VC

Voltage Divider Bias Circuit9

Voltage Divider Bias Circuit10

Simulation and Results Run DC analysis with Default Settings Observe the output on voltmeters and ammeters

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Access it Online12

You can access this experiment from the link below

http://www.docircuits.com/public-circuit/380/bjt-voltage-divider-bias